Ricardo Carvalho may be out for rest of season

Chelseaâs injury crisis has deepened after the club confirmed defender Ricardo Carvalho is expected to be out of action for at least a month.

Crocked: Ricardo Carvalho is out for at least a month – possibly longer – with an ankle injury

But the centre-half could be out for longer – possibly the rest of the season – if he requires corrective surgery on the ankle ligament damage he sustained in the first half of the 5-0 victory over Portsmouth.

Carvalhoâs setback is the latest in a long line of injury blows to Chelseaâs Barclays Premier League ambitions.

A spokesman for the club said: ‘The club will be able to determine over the next 24 hours whether the injury requires corrective surgery, however we can confirm at this point that heâll be out for at least four weeks.’

His injury leaves Chelsea with just two first-choice central defenders in Brazilian Alex and captain John Terry and comes just days after right-back Branislav Ivanovic was ruled out for a month following a knee injury sustained during the 1-1 draw at Blackburn last weekend.

Chelsea have already been without left-back Ashley Cole, midfielder Michael Essien and right-back Jose Bosingwa for much of the season.

Cole fractured his ankle, Essien collected a serious knee injury and Bosingwa needs more surgery on his ankle problem.

The latest injuries mean Chelsea will go into the decisive stage of the season, with a trip to Manchester United in eight days, and an FA Cup semi-final against Aston Villa a week later, without five first-team regulars.